Lamp construction



Patented June 28, 1932 i UNirssra-rs PATENT OFFICE.,

v HARLEY' C. FOSTER, OF CONNERSVILLE, NDANA, ASSIGNOR TO"INDIANA LAMP COR- PORATION, OF CONNERSVIIALE, INDIANA, A CORPORATION LAMP CONSTRUCTION Application led January 30,

This invention relates to a lamp construction particularly for use as a tail and stop lamp yfor automobiles. lMore particularly it relates to a type of lamp in which a stop warning is given by lighting a lamp bulb placedbehind a stencil in which is cut the word Stop or otherwarning signal The principal object of the inventionis to provide a magnifying device for the warning Signal which makes the same appear largerl than it really is at certain distances.

A feature of the invention by which this object is attained consists in the provision of a lens having magnifying properties placed before the stencil. The stencil is so positioned as to be at the focal point of the magnifying portion of the lens and hence a sharp,

clear and highly magnified image of the legend cut in the stencil is produced when the lamp bulb is lighted.

Another feature of the invention resides in the provision of a reecting surface upon the stencil member positioned behind another portion of the lens for receiving and reflecting light rays therethrough. When the lens is made, as is usually the case, of red glass,

the lights of an approaching car impinge upon this reflecting surface and are reflected thereby to produce the illusion of a lightedy tail lamp.

Another feature of the invention resides in the provision of a second bulb within the lamp adapted to project rays of light through f another portion of the lens for use as a common tail light. l

Another feature' of the invention resides in the provision of a shield member within the lens casing supported entirely by the socket-of one of said lamp bulbs for confin-` ing the light from each of said lamps to the proper portion kof the lens.

Other objects and features of the invention will be understood fromV the accompanying drawing and the following description and claim:

Fig. 1 is a central sectional view through the assembled lamp. Fig. 2 is a perspective view of the preferred form of stencil member 50 having the faceted reflecting surface. Fig. 3

.able means.

1930. Serial No. 424,472.

is a front elevational view of the preferred form of lens.

A lamp casing 10 has fastened thereto a carries a lamp bulb 16 and thesocket l15 carries a lamp bulb 17. A plug socket 18 projects through an opening in the casing 10 and yis adapted to receive a plug, not shown, for

transmitting electric current to the bulbs.- A pairof electrical conductorsv 19 conduct the said current from the unit 18 to the sockets llrand 15. l

The casing 10 is open at one end in the usual manner and the said opening is surrounded by an inturned flange 20. Adjacent the flange 2() a shoulder 21 is formed upon the casing. A stencil member 22-shown particularly in lFig. 2 is positioned abutting the flange 20 and a lens 23 abuts the said stencil member. A door rim 24v serves to maintain the stencil and lensinV placev and is fastened to the casing 10 by means of a screw 25 or other suit- The lens 23 is formed with a circular centralportion 26. -A portion of the stencil member 22 positioned behind the said portion 26. is formed with a pyramidal depression 27, the inner surfaces of which are highly polished to provide for reection. of light impinging thereon. The pyramidal ,form of the portion 27 insures that there will .be several reflecting surfaces at various angles sothat light impingingfthereon from any vdirection will be reflected inr several 'dierent ,directions and will-thus be distributed to be vvisible'from any position behind the car. The

lens 23 is preferably formed of red glass sothat thereflection from the reflectingsurface will give the illusion of a lighted tail light even though none of the bulbs are lighty If desired, however, the lens `may be of clear glass and a color filter may be interpositioned between the lens and the reflecting surface. It is not necessary that the portion 26- ofthe lens be4 in the form of a bulls-eye. as `shown in the drawing. It may be shaped as desired.v

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The lens 23 has formed about the central portion 26 an annular portion 28 having a convex outer surface and a concave inner surface. The radii of curvature of the two surfaces are different, as shown in Fig. 1, and this portion of the lens, therefore, serves to magnify any object placed adjacent thereto and in proper focus therewith. The portion of the stencil member 22 positioned immediately behind the upper part of the annular Y portion 28 of the lens has cut therein a legend 29 which may be in the form of a stop warning, an announcement of the make of the car, a trade-mark emblem or any other desired form- The said portion of the stencil member is outwardly bent as illustrated at 30 to bring the same into proper focus with respect to the magnifying portion of the lens. The bulb 16 is positioned immediately behind this portion of the stencil member and, when lighted, serves to project a magnified imageY of the legend carried thereby through the lens. The magnifying portion 28 of the lens may be formed with the inner surface flat rather than concave. In that case, the stencil may be placed flat against the lens and will be in focus when in that position.

The lower portion of the stencil member 22 adjacent the annular portion 28 of the lens has an opening 31 cut therein through which the light from bulb 17 may pass. The inner surface 32 of the lens adjacent the opening 31 is broken as illustrated in the drawing to provide diffusion of light from the bulb 17. The bulb 1'? is normally kept lighted during the hours of darkness and serves as a common tail light. A clear lens 33 is set in an openingV in the lower portion of the casing 10 adjacent the bulb 17 and serves for illumination of a number plate placed therebeneath. A shield 84C surrounds the socket 1li, is supported thereby and serves to confine the light from bulb 16 to the upper portion of the lens and that from bulb 17 to the lower portion of the lens.

Inthe manufacture of the lamp as described, the forming of the stencil member with the pyramidal or faceted reflecting sur,

that it may be supported directly upon one of the lamp sockets is also an important fac-- tor in reducing the expense of the construction.

The invention claimed is:

A lamp constructionincluding a casing having an opening therein, a lens closure for said opening having a convex outer surface for magnification, a lamp bulb within said casing, and a stencil interposed between said lens and said lamp, said stencil being shaped in approximate conformity with the inner surface of said lens to bring the same into proper focus whereby a legend formed thereon will be magnified. Y

In witness whereof, l have hereunto affixed my signature.

HARRY C. FOSTER.

Ini

faces integral therewith is an important feature. While the stencil could be cut in one member and the reliecting surfaces placed in another, such a construction would require the bolting together of the two members or the provision of some separate form of support for the reflecting surface. By the construction herein shown, on the other hand, the expense and labor is greatly reduced.

fn the foregoing description it has been assumed that the stencil member is of a thinmetallic construction with the legend cut 

